Saud Al-Mishari is updating his original content around Client Network Traffic Tests for ConfigMgr 2007, to a ConfigMgr 2012 version. He’s promised a 3-part series and has the first post up already. Saud breaks the network traffic potential down for each client activity and then separates it out into average total bytes, average client to server bytes, and average server to client bytes. It’s a good read and if you are curious as to the overall traffic consumption you’ll experience for a ConfigMgr 2012 rollout, you’ll want to stay tuned for the next two posts in the series.
Take a read through his first post: System Center 2012 Configuration Manager Client Network Traffic Estimates (Series, Part 1 of 3)